Plasma display and driving method thereof

Abstract

A plasma display device includes a plasma display panel having discharge cells formed between a plurality of first electrodes and a plurality of second electrodes and a driving circuit dividing one frame into a plurality of subfields, each subfield including a reset period, an address period, and a sustain period, and applying a driving voltage to the first electrodes and the second electrodes. During a sustain period of each subfield, a sustain discharge pulse is alternately applied to the first and second electrodes for triggering a sustain discharge. A width of a last sustain discharge pulse applied to the second electrode is set to be greater than a width of other sustain discharge pulses for selected subfields. The subfields may be selected based on whether a total number of the sustain discharge pulses during the sustain period is less than a critical number of sustain discharge pulses.

What is claimed is: 
     
       1. A method for driving a plasma display device having a plurality of first electrodes and a plurality of second electrodes, one frame for driving the plasma display device being divided into a plurality of subfields, each subfield including a reset period, an address period, and a sustain period, the method comprising, during a sustain period of each subfield among the plurality of subfields:
 alternately applying a plurality of sustain discharge pulses to the first electrode and the second electrode for triggering a sustain discharge; and 
 setting a width of a last sustain discharge pulse applied to the second electrode, the last sustain discharge pulse applied to the second electrode having a greater width than other sustain discharge pulses applied during the sustain period of the subfield when a total number of the sustain discharge pulses applied during the sustain period of the subfield is less than a predetermined number and having a width equal to the other sustain discharge pulses when the total number of the sustain discharge pulses applied during the sustain period of the subfield is greater than or equal to the predetermined number. 
 
     
     
       2. The method as claimed in  claim 1 , wherein the predetermined number of sustain discharge pulses is fifteen. 
     
     
       3. The method as claimed in  claim 1 , wherein the width of the last sustain discharge pulse applied to the second electrode is greater than 1.5 μs. 
     
     
       4. The method as claimed in  claim 1 , wherein the width of the last sustain discharge pulse applied to the second electrode is greater than 3 μs. 
     
     
       5. The method as claimed in  claim 1 , wherein a last sustain discharge pulse of the sustain period of the subfield is applied to the first electrode. 
     
     
       6. The method as claimed in  claim 5 , further comprising, during a reset period immediately following the sustain period of the subfield, gradually decreasing a voltage of the first electrode after applying the last sustain discharge pulse to the first electrode during the sustain period of the subfield. 
     
     
       7. The method as claimed in  claim 6 , wherein the first electrode is a scan electrode and the second electrode is a sustain electrode. 
     
     
       8. A plasma display device, comprising:
 a plurality of scan electrodes; 
 a plurality of sustain electrodes; 
 a controller dividing one frame into a plurality of subfields, each subfield including a reset period, an address period, and a sustain period, and grouping the plurality of subfields into a plurality of groups according to the number of sustain discharge pulses; and 
 a driving circuit applying a sustain discharge pulse to the scan electrodes and the sustain electrodes with opposite polarities during a sustain period according to a control of the controller, 
 wherein the controller sets a width of a last sustain discharge pulse applied during the sustain period to be greater than a width of other sustain discharge pulses during a sustain period of a first group among the plurality of groups, the first group having a total number of sustain discharge pulses applied during the sustain period less than a predetermined number, and to be equal to the other sustain discharge pulses during the sustain period of other groups. 
 
     
     
       9. The plasma display device as claimed in  claim 8 , wherein, in the sustain period of the first group, the last sustain discharge pulse applied to the sustain electrode is greater than 1.5 μs. 
     
     
       10. The plasma display device as claimed in  claim 9 , wherein a total number of the sustain discharge pulses applied to each subfield of the first group is less than a total number of the sustain discharge pulses applied to each subfield of a second group. 
     
     
       11. The plasma display device as claimed in  claim 10 , wherein the total number of the sustain discharge pulses applied to each subfield of the first group is less than fifteen. 
     
     
       12. The plasma display device as claimed in  claim 8 , wherein, in a reset period immediately following the sustain period, the driving circuit initializes discharge cells that have experienced a sustain discharge in the sustain period. 
     
     
       13. The plasma display device as claimed in  claim 12 , wherein the last sustain discharge pulse during the sustain period is applied to the first electrode. 
     
     
       14. The plasma display device as claimed in  claim 9 , wherein, in a reset period immediately following the sustain period, the driving circuit initializes discharge cells that have experienced a sustain discharge in the sustain period. 
     
     
       15. The plasma display device as claimed in  claim 10 , wherein, in a reset period immediately following the sustain period, the driving circuit initializes discharge cells that have experienced a sustain discharge in the sustain period. 
     
     
       16. The plasma device as claimed in  claim 8 , wherein the last sustain discharge pulse is applied to a sustain electrode. 
     
     
       17. A plasma display device, comprising:
 a plurality of first electrodes; 
 a plurality of second electrodes; 
 a controller dividing one frame into a plurality of subfields, each subfield including a reset period, an address period, and a sustain period, and grouping the plurality of subfields into a plurality of groups according to the number of sustain discharge pulses; and 
 a driving circuit applying a sustain discharge pulse, alternately having a positive first voltage and a negative second voltage, to the first electrodes and applying a third voltage to the second electrodes according to a control of the controller, 
 wherein the controller sets a width of a last sustain discharge pulse applied to the first electrodes to be greater than a width of other sustain discharge pulses for selected subfields during a sustain period of a first group among the plurality of groups. 
 
     
     
       18. The plasma device as claimed in  claim 17 , wherein the first group has a total number of sustain discharge pulses applied during the sustain period less than a predetermined number. 
     
     
       19. The plasma device as claimed in  claim 17 , wherein the first electrode is a scan electrode and the second electrode is a sustain electrode.